In a single-phase distribution grid, the nodal voltages only have statistical dependency with the nodal voltages of their parent bus [1]}. In the next part, such dependency will be extended from single-phase systems to approximate multi-phase systems' joint probability \(P(\Delta \mathbf {V}_{\mathcal {M}^+})\)  as
\(P(\Delta \mathbf {V}_{\mathcal {M}^+}) \simeq \prod _{i=1}^M P(\Delta \mathbf {V}_i|\Delta \mathbf {V}_{\text{pa}(i)}).\) 
